Japan’s Softbank Mobile has signed its first major corporate contract for the iPhone 3G, which could be a huge step for the device there. The deal will see 1,000 phones put into the hands of the top corporate bigwigs, states top technology consultant BearingPoint.

BearingPoint said it is adopting the iPhone with the aim of improving the productivity of its consultants and helping them access information more easily. Right now the consultants carry both a cellular telephone and a data modem card for a PC. The iPhone could replace both of those devices quite easily.

Unlike other nations the use of smartphones in the Japan market is still low and the iPhone has struggled for mainstream acceptance. Proprietary second-generation cellular technology left companies like Blackberry out of the market and Japanese carriers, all of which determine the specifications of handsets they sell, were slow to get going with cell phone systems running Windows Mobile. While a considerable number of Japanese handsets do run on Symbian or Linux, they are locked down so users cannot add additional programs.

Things have been slowly changing and in the last couple of years Taiwan’s High-Tech Computer has had success selling Windows Mobile-based phones to all of Japan’s cellular carriers. The first 3G Blackberry service was launched by NTT DoCoMo last year and this year’s launch of the iPhone has raised the profile of smartphones in the general eye.

Use of the iPhone by BearingPoint could help its acceptance, especially with Japanese corporations who generally avoid any sort of risk, to consider the handset alongside more business-orientated models like those from Blackberry or running Windows Mobile.